1. Field of the Invention
The present invention relates to a recording device such as an inkjet printer.
2. Description of the Related Art
Inkjet type recording devices record an image (dots) on a recording medium by reciprocating a carriage having a recording head mounted thereon, in a main-scanning direction and discharging ink droplets from a nozzle array of the recording head during this reciprocation. Then, the recording medium is fed using a feed roller or the like in a sub-scanning direction, and the recording in the main-scanning direction is repeated; thus, the image is formed on the recording medium.
Some of the aforementioned recording devices include a liquid discharge defect detection device including a light-emitting unit emitting light toward an ink droplet discharged from the nozzle array of a recording head, a light-receiving unit receiving the light emitted from the light-emitting unit, arranged so that light emitted from the light-emitting unit collides with an ink droplet, and detecting a discharge defect of the ink droplet based on an output change of the light received in the light-receiving unit (for example, see Japanese Patent Application Laid-open No. 2009-113225).
Japanese Patent Application Laid-open No. 2009-113225 has disclosed a scattering light detection type liquid discharge defect detection device. A configuration in which, for example, as illustrated in FIG. 19, scattering light components S5, S7, S9, and S11 are reflected on a reflection member 40 and converged on a light-receiving unit 33 is employed to increase an amount of scattering light received by the light-receiving unit 33. This clarifies a difference in an amount of receiving light between in the case where there is an ink droplet and in the case where there is no ink droplet. This improves reliability of detecting a liquid droplet defect.
In a general inkjet type recording device, for example, as illustrated in FIG. 20A, an ink droplet b1 is discharged from a nozzle hole Nx in a nozzle plane Hm of a recording head. Then, ink droplets b2 and b3 are successively discharged (see FIG. 20B), and unite during flight and then become one ink droplet B (see FIGS. 20C and 20D). With this ink droplet B, an image (a dot) is recorded on a recording medium. Note that as illustrated in FIGS. 20C and 20D, the ones that fly behind the ink droplet B are not united, and ink droplets that do not become the ink droplet B are called satellites Bs. Since the satellites Bs are smaller than the ink droplet B, the satellites Bs are affected easily by air resistance and soon start to float out of the flight track of the ink droplet B (see FIGS. 20E and 20F). The floating satellites B are called mist m.
In Japanese Patent Application Laid-open No. 2009-113225, the reflection member 40 is provided as illustrated in FIG. 19; therefore, because of the influence of the mist m described above, the reflection member 40 becomes dirty due to the mist m. When the reflection member 40 becomes dirty due to the mist m, it becomes impossible to efficiently converge scattering light on the light-receiving unit 33, making it difficult to clarify a difference in an amount of receiving light between in the case where there is an ink droplet and in the case where there are no ink droplets.
There is a need to provide a recording device capable of clarifying a difference in an amount of receiving light between in the case where there is an ink droplet and in the case where there are no ink droplets, without using a reflection member or the like.